Systems and methods for piston check valves

ABSTRACT

A piston check valve system includes a body including an upstream end and a downstream end, a bonnet secured to a proximal opening of the body, and a piston secured within the body, the piston being moveable between a closed position in which the piston rests upon a valve seat and an open position in which the piston is spaced away from the valve seat. The piston check valve system also includes a retainer configured to guide and retain the piston and to secure the valve seat within the body.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of and claims the benefit of priorityto U.S. application Ser. No. 17/077,549, filed Oct. 22, 2020, whichclaims the benefits of priority to U.S. Provisional Application No.62/925,654, filed on Oct. 24, 2019, the entireties of which are hereinincorporated by reference.

TECHNICAL FIELD

Aspects of the present disclosure relate generally to valves and valvesystems useful, for example, for fluid handling. In particular, aspectsof the present disclosure relate to methods and systems for piston checkvalves.

BACKGROUND

Valve devices, such as piston check valve assemblies, are useful forfluid handling in, for example, the oil and gas, power, chemical, waterworks, waste water, and manufacturing industries. Piston check valvesare robust systems that are operable to prevent backflow in fluidhandling systems located under harsh environments and operable undersevere conditions. In order to perform in these environments, valvesystems include components that are resistant to debris, corrosion, andwear. While the valve is in service, components of the valve assemblyrequire regular inspections and maintenance. Even when inspections andmaintenance are performed regularly, wear accumulates due to theoperation of moving parts of the valve, affecting locations that cannotbe accessed without disconnecting the valve device from adjacent fluidhandling components. In order to service or replace these components, itcan be necessary to disconnect the valve from upstream and downstreamcomponents. However, removing the valve from a line is a time consumingprocess that introduces significant expense.

SUMMARY

According to certain embodiments, systems and methods are disclosed fora piston check valve for fluid handling.

In one aspect, a piston check valve system may include a body includingan upstream end and a downstream end, a bonnet secured to a proximalopening of the body, and a piston secured within the body, the pistonbeing moveable between a closed position in which the piston rests upona valve seat and an open position in which the piston is spaced awayfrom the valve seat. The piston check valve system may also include aretainer configured to guide and retain the piston and to secure thevalve seat within the body.

In another aspect, a piston check valve system may include a bodyincluding an upstream opening and a downstream opening, and a pistonsecured within the body between the upstream opening and downstreamopening, the piston being moveable between a closed position in which anend face blocks a flow of fluid and an open position. The piston checkvalve system may also include a resilient member biasing the pistontowards the closed position and a cage surrounding a proximal end of thepiston, the cage including a distal bridge configured to contact anouter periphery of the end face of the piston.

In yet another aspect, a method of assembling a piston check valvesystem including a removable valve seat may include securing theremovable valve seat in a body of the piston check valve assembly andretaining the removable valve seat with a retainer that presses upon asurface of the removable valve seat. The method may also includepositioning a piston within the retainer such that the piston isconfigured to slide with respect to the retainer and securing theretainer with a bonnet.

In another aspect, a piston check valve assembly may include a body, abonnet secured to the body, a piston provided between the body and thebonnet, a retainer configured to guide and retain the piston, and aremovable valve seat.

In another aspect, a method of removing a valve seat from a piston checkvalve assembly may include separating a bonnet from a body of the pistoncheck valve assembly, removing a resilient member and a piston throughan opening in the body, separating a valve seat from the body, andremoving the valve seat through the opening.

In another aspect, a piston check valve assembly may include a body, abonnet secured to the body, a piston provided between the body and thebonnet, a retainer configured to guide and retain the piston, and avalve seat configured to form a seal with the piston, wherein the pistonis configured to travel to an upper end of the retainer when the pistoncheck valve assembly is open.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the disclosed embodiments, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate various exemplary embodiments andtogether with the description, serve to explain the principles of thedisclosed embodiments.

FIG. 1 is a downstream end view of a piston check valve system,according aspects of the present disclosure;

FIG. 2 is a cross-sectional view of the piston check valve system alongline II-II of FIG. 1 ;

FIG. 3 is an enlarged view of section III of FIG. 2 ; and

FIG. 4 is an enlarged view of section IV of FIG. 2 .

DETAILED DESCRIPTION

Both the foregoing general description and the following detaileddescription are exemplary and explanatory only and are not restrictiveof the features, as claimed. As used herein, the terms “comprises,”“comprising,” “having,” including,” or other variations thereof, areintended to cover a non-exclusive inclusion such that a process, method,article, or apparatus that comprises a list of elements does not includeonly those elements, but may include other elements not expressly listedor inherent to such a process, method, article, or apparatus. Moreover,in this disclosure, relative terms, such as, for example, “about,”“substantially,” “generally,” and “approximately” are used to indicate apossible variation of ±10% in the stated value.

FIG. 1 is a view of a piston check valve assembly 10 (e.g., showing adownstream end) according to aspects of the present disclosure. Pistoncheck valve assembly or piston check valve system 10 may include a body12, a bonnet 14, and a valve assembly or piston assembly 50. Body 12 mayinclude a pair of opposed ends formed by annular flanges or ports 130. Ahollow interior of body 12 may house piston assembly 50. Bonnet 14 maybe secured to an upper opening of body 12 to secure piston assembly 50.

Body 12 may define an upstream end 110 and a downstream end 120 (FIG. 2). Annular flanges or ports 130, formed at upstream and downstream ends110 and 120, respectively, may be sized and shaped for connection toupstream and downstream components, and may include a series of boltholes to allow ports 130 to facilitate leak-free connections to thesecomponents.

Bonnet 14 may be secured to a top surface of body 12 by a plurality offasteners 80 and fixing members 82. In the exemplary configuration shownin FIG. 1 , each fastener 80 may include a threaded bolt or stud havingan end embedded within body 12, while fixing members 82 may includerespective nuts or other suitable tightening mechanism connected to thethreading of the fasteners 80. Bonnet 14 may have an annular shape,including a proximal face 16 formed with a series of holes through whichfasteners 80 extend. Bonnet 14 may also include a bottom end or bottomface 48, and a central recess 18 (FIG. 2 ).

Body 12 may be formed of a corrosion-resistant material, such as a metalmaterial. Body 12 may be formed by carbon steel, for example. Bonnet 14may be formed of a similar material as body 12 (e.g., a metal materialsuch as carbon steel).

With reference to FIG. 2 , which is a cross-sectional view of checkvalve system 10 along line II-II of FIG. 1 , piston assembly 50 may forma one-way valve that permits flow of fluid in a flow direction fromupstream end 110 toward downstream end 120, and prohibits flow of fluidin a direction from downstream end 120 toward upstream end 110. Pistonassembly 50 may include a cage or retainer 52, a removable valve seat90, a resilient member 56, and a piston 58.

Retainer 52 of piston assembly 50 may have a substantially cylindricalbody portion, such as a proximal portion 51. A distal portion 53extending from proximal portion 51 may form a cage that includesopenings 62 separated by a series of bridges 63, such that each bridge63 is surrounded by a pair of openings. Proximal portion 51 may includea top surface that contacts bottom face 48 of bonnet 14, either directlyor via a gasket. A distal end of retainer 52, formed at the bottom ofdistal portion 53, may face valve seat 90 via a mechanism describedbelow. An interior of retainer 52 may define an axially-extendingopening within which piston 58 is moveably secured.

Piston 58 may be positioned within the opening of retainer 52 so as tobe moveable between a closed position in which piston 58 rests on valveseat 90, as shown in FIG. 2 , and an open position in which piston 58 isspaced away from and does not contact valve seat 90. A central pillar 60of piston 58 may, when piston 58 is in a closed position illustrated inFIG. 2 , be surrounded by these openings 62 and bridges 63 of retainer52. A distal end face 59, extending below central pillar 60, may blockan opening in body 12 when piston 58 rests on valve seat 90. Piston 58may be biased towards this closed position by resilient member 56.

A recess 64, formed in a proximal end of piston 58, may receive andsecure a distal end of resilient member 56, such as a spring. Recess 64may be surrounded by a rim 46 defined by piston 58. Rim 46 may define acircular surface (when viewed from above) that opposes the face 48 ofbonnet 14. A proximal end of resilient member 56 opposite rim 46 may befixed to bonnet 14 and may extend within a central recess 18 defined bybonnet 14. When bonnet 14 is secured to body 12, recess 18 may face theinterior of body 12 and piston 58.

Below resilient member 56, a body of piston 58 itself may furtherinclude one or more ball check valves 70 (e.g., configured to relieveexcess pressure), and an orifice fitting 72, which may each beaccessible via recess 64. One or more piston rings 68 may be provided inan outer circumference of a proximal portion of piston 58 to facilitatesliding motion of piston 58 within retainer 52. A distal end face 59 ofpiston 58 may include an outer circumference configured to sealinglycontact seat 90 at a peripheral surface of end face 59, while a centralportion of face 59 faces downward toward a bottom of body 12. The outerperiphery of end face 59 may include a tapered surface or chamfer forcontacting seat 90, as described below.

A vent fitting 84 may be secured so as to extend through a center ofproximal face 16 of bonnet 14. Vent fitting 84 may be configured torelieve excess pressure within retainer 52. For example, vent fitting 84may be in communication with the interior of retainer 52 and may relievepressure within retainer 52 when piston 58 moves proximally and reducesthe size of a chamber between piston 58 and bottom face 48 of bonnet 14.

A force of resilient member 56, such as a spring force, may besufficient to close piston assembly 50 and block reverse or upstreamflow of fluid in a direction from downstream end 120 toward upstream end110. A sufficient flow in an opposite direction may be permitted. Forexample, when fluid (e.g., oil, other petroleum products, water, etc.)introduced from upstream end 110 applies sufficient force on end face59, piston 58 may move proximally (upwards in FIG. 2 ) so as to allowfluid communication in a direction from upstream end 110 towarddownstream end 120.

Resilient member 56 may have a resistive force (e.g., spring force)selected to allow piston 58 to move proximally such that rim 46 isbrought into contact with face 48 of bonnet 14. Piston assembly 50 maybe configured to allow piston 58 to travel an entire length of pistonassembly 50 that is defined by retainer 52. For example, resilientmember 56 may be configured to permit piston 58 to travel to a fullyopen position in which end face 59 contacts bottom face 48 of bonnet 14,as described below.

At each position of piston 58, including a fully-open position where rim46 contacts face 48, piston 58 may be aligned within retainer 52. Inparticular, when piston 58 abuts bonnet 14, piston 58 may have noangular tilt or substantially no angular tilt with respect to an axialdirection defined by retainer 52 (e.g., a proximal to distal directioncorresponding to the vertical axis in FIG. 2 ). When piston 58 abutsseat 90, piston 58 may also have no angular tilt or substantially noangular tilt with respect to this axial direction.

During movement of piston 58, bridges 63 may guide an outercircumference of the distal end portion of piston 58 while cylindricalproximal portion 51 of retainer 52 guides the outer circumference of theproximal end portion of piston 58. This may prevent vibration andchatter of piston 58 within retainer 52. Thus, the proximal and distalportions of piston 58 may remain aligned and prevented from tilting whenin the closed position, the fully-open position, and in eachintermediate position therebetween. In at least some configurations,this alignment may tightly secure piston 58 within retainer 52.Additionally, piston rings 68 may be formed of a low-friction materialconfigured to slide along an inner peripheral surface of retainer 52, soas to reduce friction and wear.

Valve seat 90 may be a ring-shaped member inserted within a recess ofbody 12. Valve seat 90 may be formed of a suitable corrosion andwear-resistant material that is suitable for repeated contact with theangled or chamfered surface of face 59 of piston 58. Valve seat 90 maybe formed of a suitable metal material, such as a material includingcarbon steel. In some aspects, valve seat 90 may include a polymericmaterial, such as polytetrafluoroethylene (PTFE), polyether ether ketone(PEEK), other polymers, and composites thereof. Valve seat 90 may becoaxially disposed with respect to retainer 52 and opening 13.

Retainer 52 may be configured to press upon and secure seat 90 withinbody 12 while remaining stationary during operation of piston assembly50. Retainer 52 may be secured by bottom face 48 of bonnet 14, whichpresses upon retainer 52 and urges retainer 52 in a distal direction(e.g., by applying a pre-determined torque to fixing members 82). Due tothe force applied to the end of proximal portion 51 of retainer 52, asbest shown in FIG. 4 , an end of distal portion 53 may press upon aproximal-facing surface of seat 90, securing seat 90 within a recess ofbody 12. Thus, retainer 52 may form a containment device that securesseat 90.

The assembly of retainer 52 and seat 90 may further facilitate reductionin chatter and vibration, even when valve system 10 is in a partially orfully open state, and during transitions between closed and open states.In some aspects, by applying a pressing force to seat 90, seat 90 may befirmly secured to body 12, without the need to be permanently attachedto body 12 (e.g., by welding). This may facilitate removal of seat 90when necessary, as described below. Additionally, reducing oreliminating vibration in this manner may reduce noise and extend thelife of piston assembly 50 by reducing wear on piston 58, retainer 52,and valve seat 90.

As shown in FIGS. 2 and 3 , bonnet 14 may be fixed to an upper surfaceof body 12 so as to protrude within opening 13 of body 12. Withreference to FIG. 3 , a gasket 86 and an O-ring 88 may be provided toseal the interface between body 12 and bonnet 14. Gasket 86 may extendcircumferentially along an interface between bonnet 14 and body 12.Gasket 86 may form a seal between a distally-facing surface of bonnet 14and a proximally-facing surface of body 12. One or more additionalsealing members, such as O-rings 88, may be placed within respectiverecesses of bonnet 14. Additionally or alternatively, one or moreO-rings 88 may be placed within one or more recesses of body 12.Resilient sealing members, such as O-rings 88, may form a seal between aradially-inwardly facing surface of body 12 and a corresponding surfaceof bonnet 14.

FIG. 4 is a cross-sectional view of piston assembly 50 when in theclosed position, showing exemplary positions of piston 58, retainer 52,and seat 90. When piston assembly 50 is closed, retainer 52 and seat 90may each surround part of the distal end portion of piston 58. Inparticular, seat 90 may extend distally of retainer 52 so as to surroundthe distal end of piston 58, including end face 59. A sealing surface 95of valve seat 90 may be shaped to receive a mating surface of piston 58.Sealing surface 95 may include a surface having a substantially circularshape when viewed from above. Sealing surface 95 may be an inclined orchamfered surface formed at an inner periphery of seat 90. Piston 58 maybe brought into contact with sealing surface 95 of valve seat 90 whenpiston 58 blocks the flow of fluid in an upstream direction. Thus, eachtime piston assembly 50 transitions from an open position to a closedposition, piston 58 may impact sealing surface 95.

A clearance or gap 96 may be present at one or more locations betweenpiston 58 and retainer 52. Gap 96 may be formed between one or moreareas where piston 58 is out of contact, or in discontinuous contact,with retainer 52. While not shown in FIG. 4 , piston 58 may also contactretainer 52 at one or more locations of distal portion 53, such asbridges 63. Distal portion 53 of retainer 52 may be sized so as toprevent significant inclination of piston 58 with respect to a verticaldirection (as represented by the vertical axis extending through piston58 FIG. 2 ).

As discussed above, bonnet 14 may apply a force to retainer 52 thatpresses retainer 52 against valve seat 90. This force may be transferredfrom retainer 52 to seat 90 at an interface between these twocomponents, as shown in FIG. 4 . For example, retainer 52 may include anouter retainer recess 76 and an inner retainer protrusion 78 at theinterface between retainer 52 and seat 90. Seat 90 may include an innerseat recess 55 and an outer seat protrusion 57, such that seat recess 55faces and receives retainer protrusion 78, while seat protrusion 57faces and is received by retainer recess 76. Seat protrusion 57 may beformed by a lip or ridge on a radially peripheral portion of seat 90.Retainer protrusion 78 may press upon the surface of recess 55. While agap may be present between recess 76 and protrusion 57 as shown in FIG.4 , protrusion 57 and recess 76 may be sized so as to contact eachother. Additionally or alternatively, the locations of protrusions 57and 78 (and recesses 55 and 76) may be reversed, such that retainer 52includes a protrusion at the radially-outer portion thereof and seat 90includes a recess at a corresponding outer portion.

Valve seat 90 may include an outer circumferential surface 102 thatextends about an outer periphery of the ring-shaped seat 90.Circumferential surface 102 may face body 12 so as to form an interface92, as shown in FIG. 4 . Interface 92 between seat 90 and body 12 may befree of welding, or other mechanisms for permanently fixing seat 90 tobody 12. In some aspects, seat 90 may be secured at interface 92 by theforce applied by retainer 52. Thus, valve seat 90 may be secured so asto abut body 12 in a manner that allows removal of valve seat 90 withoutthe need to use cutting tools to separate seat 90 from body 12.

A distal or bottom end of valve seat 90 may include an annular surface104. Annular surface 104 and body 12 may form an interface 94 at whichannular surface 104 of seat 90 contacts a supporting surface formedwithin a recess of body 12. Like interface 92, interface 94 may be freeof welding or other mechanisms for permanently fixing seat 90 to body12. Thus, an entirety of seat 90 may be free of welds. If desired, asealing member 88 may be placed below circumferential surface 102 andbetween seat 90 and body 12.

An exemplary process for assembling valve system 10 may includeassembling valve seat 90 within body 12 in a manner that facilitatessubsequent removal. Valve seat 90 may be positioned within body 12 byinserting valve seat 90 through opening 13 (FIG. 2 ). Valve seat 90 maybe placed within a recess of body 12, such that valve seat 90 contactsbody 12 as shown at interfaces 92 and 94 (FIG. 4 ). If desired, anO-ring 88 may be sandwiched between body 12 and valve seat 90 to preventthe occurrence of leaks. With valve seat 90 positioned within body 12,piston assembly 50 may be inserted into body 12. For example, retainer52, piston 58, and resilient member 56 of piston assembly 50 may beinserted through opening 13. Bonnet 14 may be brought into tension viaone or more fasteners 80 and fixing members 82, such that a portion ofretainer 52, such as protrusion 78, tightly secures valve seat 90 tobody 12.

During operation of valve system 10, and with reference to FIG. 2 , aflow of fluid from upstream end 110 toward downstream end 120 may applyan upward force to end face 59 of piston 58. This force may urge piston58 against the force of resilient member 56, such that piston 58 movesupwards in a manner that compresses resilient member 56. In someaspects, the pressure of fluid may be sufficient to cause piston 58 tomove a full length of the cage or retainer 52. This may bring, forexample, rim 46 into contact with face 48. When the force of fluidentering via upstream end 110 drops below the amount of force exerted byresilient member 56, including when flow stops or reverses, piston 58descends onto seat 90, blocking the reverse flow of fluid. Over time,repeated openings and closings of piston assembly 50 may cause seat 90to accumulate wear (e.g., on a sealing surface 95).

A method or process for removing and/or replacing valve seat 90 fromcheck valve system 10 may be performed while valve system 10 remainsconnected to upstream and downstream components of a pipeline, such asone or more components secured to ports 130. Once a supply of fluid toupstream end 110 has been discontinued, fasteners 80 and fixing members82 may be removed, after which bonnet 14 may be separated from body 12so as to release the force retaining valve seat 90. With fasteners 80and fixing members 82 removed, components of piston assembly 50 may beseparated from body 12 and withdrawn through opening 13, includingresilient member 56, piston 58, and retainer 52. Valve seat 90 may thenbe removed through opening 13 without the need to separate a bond, suchas a weld, between body 12 and seat 90. A replacement valve seat 90 maythen be inserted through the upper opening of body 12, and the remainingcomponents of piston assembly 50 may be assembled within body 12, asdescribed above. In an alternative configuration, valve seat 90 may beremovable, together with retainer 52, through opening 13. Regardless ofwhether valve seat 90 is removed separately or together with retainer52, the process for removing and/or replacing valve seat 90 may beperformed inline (e.g., without removing valve system 10 from a seriesof connected pipeline components).

It will be apparent to those skilled in the art that modifications maybe made in the disclosed systems and methods without departing from thescope of the disclosure. Other aspects of the disclosure will beapparent to those skilled in the art from consideration of thespecification and practice of the features disclosed herein. It isintended that the specification and embodiments be considered asexemplary only.

What is claimed is:
 1. A piston check valve, comprising: a body; anupstream flange; a downstream flange, the downstream flange beingdisposed opposite the upstream flange; a bonnet secured to the body; apiston including a proximal end that faces the bonnet and a distal endthat faces a portion of the body, the piston having a central pillarforming a narrowed portion connected to and extending axially betweenthe proximal end and the distal end of the piston; a retainer thatsurrounds the proximal end, the central pillar, and the distal end ofthe piston; and a valve secured to the piston.
 2. The piston check valveof claim 1, further including a resilient member positioned between thecentral pillar and the bonnet.
 3. The piston check valve of claim 2,wherein the piston includes a recess, the resilient member extendingwithin the recess of the piston.
 4. The piston check valve of claim 1,wherein the retainer includes a plurality of openings defined by bridgesof the retainer that respectively surround each opening.
 5. The pistoncheck valve of claim 4, wherein the piston is movable between a closedposition and an open position such that, when the piston is in theclosed position, the central portion of the piston is surrounded by thebridges and the openings.
 6. The piston check valve of claim 1, furtherincluding an upstream opening surrounded by the upstream flange and adownstream opening surrounded by the downstream flange, the upstreamopening overlapping the downstream opening in a lateral direction thatis orthogonal to a proximal-distal direction.
 7. The piston check valveof claim 6, wherein the upstream flange and the downstream flange arepositioned at the same height as measured in the proximal-distaldirection.
 8. The piston check valve of claim 1, further including avent fitting connected to a proximal face of the bonnet.
 9. A pistoncheck valve, comprising: a body; an upstream opening; a downstreamopening; a piston having a proximal end portion, a distal end portion,and an axially-central pillar between the proximal end portion and thedistal end portion, the piston being secured within the body between theupstream opening and the downstream opening and being movable between aclosed position and an open position; a resilient member biasing thepiston towards the closed position; a check valve connected through aportion of the piston; a retainer contacting the proximal end portion ofthe piston; and a removable valve seat having an opening sized toreceive the distal end portion of the piston when the piston is in theclosed position.
 10. The piston check valve of claim 9, wherein theopening of the removable valve seat is formed by an inclined surfaceconfigured to form a seal with the distal end portion of the piston. 11.The piston check valve of claim 9, wherein the proximal end portion ofthe piston includes a piston ring that contacts the retainer.
 12. Thepiston check valve of claim 9, wherein the retainer contacts the distalend portion of the piston.
 13. The piston check valve of claim 9,wherein the upstream opening overlaps the downstream opening in alateral direction that is orthogonal to a proximal-distal direction. 14.The piston check valve of claim 13, wherein the upstream opening and thedistal opening overlap the removable valve seat in the lateraldirection.
 15. The piston check valve of claim 14, further including aprotrusion extending from one of the valve seat or the retainer in theproximal-distal direction.
 16. The piston check valve of claim 15,further including a recess in the other of the valve seat or theretainer that receives the protrusion.
 17. A piston check valve,comprising: a body; an upstream end; a downstream end disposed oppositethe upstream end in a lateral direction; a piston between the upstreamend and the downstream end in the lateral direction, the piston having acentral pillar extending from a distal end portion of the piston; aretainer that surrounds the piston; a check valve in the piston andoffset from the central pillar; and a valve seat having a ring-shapedproximal end portion that contacts the retainer, the proximal endportion of the valve seat having a sealing surface configured to contactthe distal end portion of the piston when the piston check valve isclosed so as to block a flow of fluid from the upstream end to thedownstream end.
 18. The piston check valve of claim 17, wherein theretainer includes a plurality of openings extending between bridges ofthe retainer.
 19. The piston check valve of claim 18, wherein theopenings surround the central pillar of the piston when the piston checkvalve is closed.
 20. The piston check valve of claim 19, wherein theopenings surround the distal end portion of the piston when the pistoncheck valve is open.